Field of the Invention
The present invention relates to systems and methods for preparation and use of cold atmospheric plasma stimulated media for cancer treatment.
Brief Description of the Related Art
During the past decade, cold atmospheric plasma (CAP), a near room temperature plasma mainly composed of reactive oxygen species (ROS) and reactive nitrogen species (RNS), has been investigated for its promising application in anti-cancer therapy. See Kalghatgi, S. et al. Effects of non-thermal plasma on mammalian cells. PloS one 6, e16270 (2011); Ratovitski, E. A. et al. Anti-Cancer Therapies of 21st Century: Novel Approach to Treat Human Cancers Using Cold Atmospheric Plasma. Plasma Processes and Polymers 11, 1128-1137 (2014); and Fridman, G. et al. Floating Electrode Dielectric Barrier Discharge Plasma in Air Promoting Apoptotic Behavior in Melanoma Skin Cancer Cell Lines. Plasma Chemistry and Plasma Processing 27, 163-176 (2007). So far, CAP has shown a significant anti-cancer capacity over a wide range of cancer cell lines, including carcinomas, melanomas, neuroectodermal malignancies, and hematopoietic malignancies. See, Ahn, H. J. et al., “Atmospheric-pressure plasma jet induces apoptosis involving mitochondria via generation of free radicals,” PloS one 6, e28154 (2011); Yan, X. et al., “Plasma-Induced Death of HepG2 Cancer Cells: Intracellular Effects of Reactive Species,” Plasma Processes and Polymers 9, 59-66 (2012); Kim, G. C. et al., “Air plasma coupled with antibody-conjugated nanoparticles: a new weapon against cancer,” Journal of Physics D: Applied Physics 42, 032005 (2009); Lee, H. J. et al., “Degradation of adhesion molecules of G361 melanoma cells by a non-thermal atmospheric pressure microplasma,” New Journal of Physics 11, 115026 (2009); Tanaka, H. et al., “Plasma-Activated Medium Selectively Kills Glioblastoma Brain Tumor Cells by Down-Regulating a Survival Signaling Molecule, AKT Kinase,” Plasma Medicine 1 (2011); Xiaoqian, C. et al., “Synergistic effect of gold nanoparticles and cold plasma on glioblastoma cancer therapy,” Journal of Physics D: Applied Physics 47, 335402 (2014); Thiyagarajan, M., Waldbeser, L. & Whitmill, A., “THP-1 leukemia cancer treatment using a portable plasma device,” Studies in health technology and informatics 173, 515-517 (2011); and Barekzi, N. & Laroussi, M., “Dose-dependent killing of leukemia cells by low-temperature plasma,” Journal of Physics D: Applied Physics 45, 422002 (2012). In addition, the CAP also strongly resists tumor growth in mice. Several general conclusions about the anti-cancer mechanism of CAP have been acknowledged. First, the rise of intracellular ROS always occurs in cancer cells upon CAP treatment, which causes a noticeable damage on the antioxidant system and subsequently DNA double strands break (DSB) to a fatal degree. See, Zhao, S. et al., “Atmospheric pressure room temperature plasma jets facilitate oxidative and nitrative stress and lead to endoplasmic reticulum stress dependent apoptosis in HepG2 cells,” PloS one 8, e73665 (2013); Kaushik, N. K., Kaushik, N., Park, D. & Choi, E. H., “Altered Antioxidant System Stimulates Dielectric Barrier Discharge Plasma-Induced Cell Death for Solid Tumor Cell Treatment,” PloS one 9, e103349 (2014); and Koritzer, J. et al., “Restoration of sensitivity in chemo-resistant glioma cells by cold atmospheric plasma,” PloS one 8, e64498 (2013). Second, serious DNA damage and other effect of CAP on cancer cells result in the cell cycle arrest, apoptosis or necrosis with a dose-dependent pattern. Volotskova, O., Hawley, T. S., Stepp, M. A. & Keidar, M., “Targeting the cancer cell cycle by cold atmospheric plasma,” Scientific reports 2, 636 (2012); Kim, J. Y., Kim, S.-O., Wei, Y. & Li, J., “A flexible cold microplasma jet using biocompatible dielectric tubes for cancer therapy,” Applied Physics Letters 96, 203701 (2010); and Ma, R. N. et al., “An atmospheric-pressure cold plasma leads to apoptosis in Saccharomyces cerevisiae by accumulating intracellular reactive oxygen species and calcium,” Journal of Physics D: Applied Physics 46, 28540 (2013). Third, among diverse reactive species generated in CAP, H2O2 and NO are proposed to be key molecules to kill cancer cells. See, Bekeschus, S. et al., “Hydrogen peroxide: A central player in physical plasma-induced oxidative stress in human blood cells,” Free Radical Research 48, 542-549 (2014). Fourth, untransformed normal cells always show stronger resistance to CAP than cancer cells do. Such killing preference on cancer cells is always accompanied with the distinct ROS levels and DSB among cancer cells and normal cells. Georgescu, N. & Lupu, A. R., “Tumoral and normal cells treatment with high-voltage pulsed cold atmospheric plasma jets,” Plasma Science, IEEE Transactions on 38, 1949-1955 (2010); Zucker, S. N. et al., “Preferential induction of apoptotic cell death in melanoma cells as compared with normal keratinocytes using a non-thermal plasma torch,” Cancer biology & therapy 13, 1299-1306 (2012); and Ja Kim, S., Min Joh, H. & Chung, T. H. “Production of intracellular reactive oxygen species and change of cell viability induced by atmospheric pressure plasma in normal and cancer cells,” Applied Physics Letters 103, 153705 (2013).
Conventionally, the CAP is directly used to irradiate cancer cells or tissue. Over past three years, the CAP irradiated media was also found to kill cancer cells as effectively as the direct CAP treatment did. Yan, D. et al., “Controlling plasma stimulated media in cancer treatment application,” Applied Physics Letters 105, 224101 (2014). In contrast to the direct CAP treatment, CAP stimulated (CAPS) media has advantages. The CAPs media can be stored in the refrigerator and maintain its anti-cancer capacity for at least 7 days. Adachi, T. et al., “Plasma-activated medium induces A549 cell injury via a spiral apoptotic cascade involving the mitochondrial-nuclear network,” Free radical biology & medicine 79C, 28-44 (2014). Thus, the CAPs media might be a good fit for the condition where a CAP device is not available. Moreover the CAPs media can be injected into tissues and effectively prevent tumor growth. Utsumi, F. et al., “Effect of indirect nonequilibrium atmospheric pressure plasma on anti-proliferative activity against chronic chemo-resistant ovarian cancer cells in vitro and in vivo,” PloS one 8, e81576 (2013). These tissues may not be easily penetrated by the CAP jet, which only causes the cell death in the upper 3-5 cell layers of the CAP touched tissues. Partecke, L. I. et al., “Tissue tolerable plasma (TTP) induces apoptosis in pancreatic cancer cells in vitro and in vivo,” BMC cancer 12, 473 (2012). To date, the anti-tumor capacity of the CAPs media has been researched less than the direct CAP treatment. Therefore, basic principles to guide its application remain elusive.